Abrading implement



April 3, 1962 A. FIELD 3,027,692

ABRADING IMPLEMENT Filed 001;. 7', 1960 3,027,692 ABRADING IMPLEMENTAlbert Field, 1706 Salem Ave., Dayton, Ohio Filed Oct. 7, 1960, Ser. No.61,116 15 Claims. ((31. 51-190) This invention relates to abradingimplements, and particularly to drum sanders wherein a cylindrical bandmade of an abrasive coated fabric is installed on a rotary mandrel forinternal sanding and finishing operations. While not so limited theinvention has especial reference to machine mounted implements whereinthe work is brought to the tool rather than the tool to the work.

Devices of the kind of which the instant invention relates hold theabrasive coated hand through the application of outwardly directedforces of expansion, and it is an objective in the design of suchdevices to enable these forces to be readily released and reapplied inorder that worn bands may quickly and easily be removed and replaced.

An object of the instant invention is to achieve design improvement inthis respect, lending the concept of simplified band installation andreplacement to relatively large drum sanders of the machine mountedtype.

Another object of the invention is to effect improvement in the safetycharacteristics of devices as described, particularly in respect of theobviating of projecting portions of the rotary mandrel, it beingcontemplated that the operating controls for tightening and releasing aband upon the mandrel be comprised wholely within the dimensions of theband.

Other objects and structural details of the invention will appear fromthe following description when read in connection with the accompanyingdrawing, wherein:

FIG. 1 is a view in exploded perspective of a drum sander in accordancewith the illustrated embodiment of the invention;

FIG. 2 is a view in longitudinal section of an assembled device as shownin FIG. 1;

FIG. 3 is a detail view in front elevation of an adjustment nutcomprised in the device; and

FIG. 4 is a view like FIG. 3 showing a part which in the assembly of thedevice occupies a companion interfitting relation to the part of FIG. 3.

Referring to the drawing, an abrading implement in accordance with theillustrated embodiment of the invention is adapted for installation uponthe outer end of a machine driven shaft 10. It has a unitary structuralcharacter, the principal support being a mandrel 11. One end of thelatter is formed with a polygonal head 12 having an axial threadedrecess 13 receiving the correspondingly threaded end of the shaft insuch manner as detachably to connect the unitary abrading implement tothe machine shaft for rotation thereby.

The mandrel 1 1 is formed over the greater part of its length with acylindrical shank portion 14. This portion terminates in a shoulder 15beyond which the mandrel is formed with a reduced diameter projectingthreaded stud 16. Mounted on the shank portion 14 is a cylindricalmember 17 made up of a core body portion 18, and, overlaying such corebody a peripheral body portion 19. The body 18 and portion 19 are madeof resilient materials and are united with one another by a suitablebonding or like operation. Peripheral portion 19 is, however,differentiated from the body portion 18 by being made of a softer morereadily deformable material. A liner 21 protects the material of themember 17 from direct contact with the mandrel 11. Interposed betweenthe cylindrical member 17 and the head 12 of the mandrel 11 is a disc 22performing a back-up or reactant function in connection with member 17,and particularly with respect ire S it-ates atent to peripheral portion19, the disc 22 having its peripheral edge turned inward to define aprojecting flange 23 engaging the peripheral portion 19 and holding thebody 18 normally spaced from the back-up disc.

Beyond the cylindrical member 17, on the mandrel 11, is a companion andmating cylindrical member or assembly 24 which includes a nut 25 havinga threaded mounting on the stud 16. Further comprised in the assembly 24is a cylindrical body 26 made of a resilient material like the materialof body portion 18 and corresponding in its outside diameter to thediameter of member 17. The members 17 and 24 are in end to end relationupon the mandrel 11, and, with their adjacent faces or ends incontacting relation, present through their joint peripheries acontinuous elongated exterior bearing surface.

The body 26 is formed with a longitudinal through cylindrical bore 27,and, in its outer face a counter-bore 28 having a polygonalconfiguration. The nut 25 has a cylindrical portion 29 matching andadapted to be received in bore 27 as well as an enlarged polygonalportion 31 adapted to be received in and interfit with the noncircularcounter-bore 28. Still further in the outer end or face of the body 26is a broad recess 32 receiving another back-up disc or pressure plate 33which is integrally formed with or otherwise secured to the nut 25.

The construction and arrangement of parts accordingly is one placing thecylindrical members 17 and 24 in end to end relatively rotatablerelation upon the mandrel 11. In response to a gripping and ttuning ofthe cylindrical member 24 the nut 25 forming a part thereof rotates uponthe threaded stud 16 and so effects an axial motion of the member 24toward or away from the member 17. In response to motion effecting anapproach of the member 24 to the member 17, body 26 contacts the body18- 19, and, as such motion is continued, efiects a longitudinalcompression of the material of these bodies as it is clampingly engagedbetween the back-up disc 22 and the pressure plate 33. In responsethereto the cylindrical bearing surface at the exterior of the deviceexpands, the peripheral portion 19 of the member 17 providing quickresponse to the application of such longitudinal pressures. Continuedapplication of such pressure may thrust the member 17 into fullengagement with the back-up disc 22, and a limit to such motion isrepresented by the shoulder 15 on the mandrel 11 engageable by the nut29..

In the use of the abrading implement the companion cylindrical members17 and 2e are surrounded by a flexible band 34 made of a fabric or likematerial and coated with an abrasive product. The band 34 isapproximately coextensive in length with the combined lengths of themembers 17 and 24 and seats on the circular bearing surface provided bysuch members. In the installation of the band, the cylindrical member 24is backed oil or relatively retracted relatively to the member 17 sothat the band may he slid freely to position upon the bearing surface.After it has been so positioned the body 26 is grasped by the operator,the pressure of such grasp being applied directly through the flexibleband 34, and the body is turned, along with the band. In response tosuch motion, as noted, a pressural engagement is effected between thebodies 26 and 1819 with a consequent expansion of at least a part of theperipheral bearing surface. This outward thrust applies a hoop tensionto the band 34 in such manner as frictionally to hold it to the mandreland parts mounted thereon. In this connection it will be observed thatthe body 26 of member 24 has a positive driving connection with themandrel 11 and in turn is frictionally engaged with the member 17 inresponse to its movement locking up the band 34 thereon. Accordinglyboth assemblies 17 and 24 rotate in unison with the mandrel 11. Thedrive through the mandrel to the rotating bodies thereon is, moreover,entirely contained within the dimensions of the band 34, as is thecontrol whereby the band alternately is locked to and released from themandrel. No projections at the outer end of the mandrel or of theabrading implement, which may present safety hazards, are required.

What is claimed is:

1. An abrading implement, including a pair of cylindrical members in endto end relation, the peripheries of said members combining to form alongitudinally elongated circular bearing surface, an abrasive coatedband in surrounding contacting relation to said bearing surface, amandrel serving as an axial support for said members, one of saidmembers having a screw threaded connection with said mandrel to apply alongitudinal thrust to the other member in response to rotation of saidone member on said mandrel in one direction, and means for limitinglongitudinal motion of the other one of said members in response to suchthrust, the peripheral portion of at least one of said members beingmade of a resilient deformable material compressed by thrust engagementof said members to expand at least a portion of said bearing surfaceinto tighter fitting contact with the abrasive coated band.

2. An abrading implement, including a pair of cylindrical members in endto end relation, 21 mandrel serving as an axial support for saidmembers, means on said mandrel limiting longitudinal motion of one ofsaid members in one direction, a threaded connection between saidmandrel and the other one of said members, said one member beingrotatably adjustable to effect in conjunction with said limiting meansan endwise clamping of said one member, a peripheral portion of said onemember being made of a resilient deformable material expanding undersuch clamping pressure, and the periphery of said other member combiningwith the periphery of said one member to form an abrasive band bearingsurface.

3. An abrading implement, including a pair of relatively rotatablecylindrical members in end to end relation, said members being ofsubstantially equal diameter to present on their exteriors alongitudinally elongated circular bearing surface, at least one of saidmembers having its exterior bearing portion formed of a resilientdeformable material, and means providing a common support for saidmembers and a backing for one end of one of said members, the othermember being in threaded engagement with said support and rotatable toapply and 10 release a clamping pressure to the opposite end of said onemember whereby selectively to expand said bearing surface in the regionof said resilient deformable material.

4. An abrading implement according to claim 3, characterized in thatsaid one member is long in relation to said other member and formed withsaid resilient deformable bearing portion, said other member beingadjacent to said one member and rotated by a manual grasp of itsexterior.

5. An abrading implement according to claim 3, characterized by aflexible abrasive coated band in surrounding contacting relation to saidbearing surface and tightened thereon by expansion of said surfaces, theexterior of said other member being adapted to be gripped through saidband for rotation.

6. An abrading implement according to claim 3, characterized in thatsaid other member is comprised of a nut in screw threaded engagementwith said support, a ring made of resilient material installed on saidnut for relative longitudinal and unison rotary motions and a flangeintegral with said nut in backing relation to one end of said ring theother end of the ring extending into contacting relation to said onemember and the periphery forming a part of said bearing surface.

7. An abrading implement, including a mandrel, a cylindrical member onsaid mandrel havin a body formed of a resilient material and aperipheral portion formed of another and softer resilient material, aback-up means for one end of said member mounted on said mandrel to forma part thereof and having an inwardly directed flange aligned with saidperipheral portion of softer material, and means mounted on said mandrelbeyond said cylindrical member and movable longitudinally thereof toapply to said member in conjunction with said back-up means and endwiseclamping pressure expanding radially outward the peripheral portionthereof.

8. An abrading implement according to claim 7, characterized in thatsaid last named means includes a cylindrical body adapted to make aflush end to end contact with said cylindrical member and having aperiphery aligned with and serving as an extension of the periphery ofsaid cylindrical member, said peripheries cooperating to form a circularbearing surface which is at least in part radially expansible.

9. An abrading implement according to claim 7, characterized in thatsaid last named means includes an assembly comprising a nut in screwthreaded engagement with said mandrel and a body made of a resilientmaterial and non-rotatably mounted on said nut, said body having adiameter equal to that of said cylindrical member and making a flush endto end engagement with said cylindrical member, the periphery of thebody comprised in said assembly presenting a gripping area for manualturning of the assembly comprising said body and said not and furtherdefining a continuation of the periphery of said cylindrical member todefine therewith an elongated circular bearing surface.

10. An abrading implement according to claim 9, characterized by meanson said mandrel engageable by said nut to limit the extent of relativerotary motion of said assembly in one direction.

ll. An abrading implement, including a mandrel, a cylindrical member onsaid mandrel having a body formed of a resilient material, and havinginner and outer ends, back-up means on said mandrel for the inner end ofsaid cylindrical member, another cylindrical member on said mandrel in aposition of alignment with the first said member and having an inner endfacing the outer end of the first said cylindrical member, a nut inscrew threaded engagement with said mandrel and mounting said othercylindrical member for unison rotation, said not having an integralportion extending in back-up relation to the outer end of said othercylindrical member, said other cylindrical member being made of aresilient material and having a diameter equal to that of the first saidcylindrical member to define therewith a substantially continuouscircular bearing surface caused selectively to expand and to contract bya manual grasping of said other cylindrical member and rotating it uponsaid mandrel into and out of endwise clamping engagement with the firstsaid cylindrical member.

12. An abrading implement according to claim 11, characterized by meanson said mandrel cooperating with said not to limit relative rotarymotion of said other cylindrical member in one direction.

13. An abrading implement, including a mandrel, a nut threaded on saidmandrel and having a radially projecting pressure plate, a reactant discon said mandrel in longitudinal spaced relation to said pressure plate,and a two part body of resilient deformable material mounted on saidmandrel between said pressure plate and said disc, one part of said bodybeing connected to said nut for unison rotation whereby relative rotarymotion of said one part in one direction completes a rotary drive fromsaid mandrel through both parts of said body and radially expands saidbody.

14. An abrading implement according to claim 13, characterized in thatsaid one part of said body occupies a complementary position to theother part to form an abrasive band support and presents a relativelylarge peripheral surface for the grasp of the operator for turningmotion as described.

15. An abrading implement, including a pair of body members in end toend relation, said members being circular in cross-section and theirperipheries being continuations of one another to form a longitudinallyelongated bearing surface, an abrasive coated band in surroundingcontacting relation to said bearing surface, a mandrel serving as anaxial support for said body members, a nut rotatably mounted on saidmandrel in threaded engagement therewith and connected to one of saidbody members for unison rotation, rotation of said one body member inone direction turning said nut on said mandrel to cause said one bodymember to advance on the other said body member, and means for limitingmovement of said other body member under thrust engagement by said onebody member, at least a part of said longitudinally elongated bearingsurface being comprised of a resilient deformable material compressed bythrust engagement of said members to expand at least a portion of saidbearing surface into tighter fitting contact with the abrasive coatedband.

References Cited in the file of this patent UNITED STATES PATENTS2,892,292 Whitney June 30, 1959

